(1) Field of the Invention
This invention relates in general to an electrical switch means and more particularly to a switch for use with film circuits.
(2) Description of the Prior Art
Many different kinds of switching devices are known which are used in electrical circuits for switching elements in or out of circuits thereby selectively changing circuit values. This holds true in thick/thin film circuits where it has been found to be advantageous to selectively add or subtract circuit elements allowing the circuit to operate in several different input-output configurations.
Former methods of accomplishing switching functions in thick/thin film circuits were to solder and de-solder wire conductors between solder pads or to use commercial switches either soldered to the substrate or outboarded.
The disadvantages of soldering and de-soldering conductor wire is an obvious one. This method is time consuming and requires special equipment. Special care in soldering minute circuits is required which becomes increasingly difficult to perform on circuits mounted onto an assembly. In addition the number of soldering operation which can be performed is extremely limited, as molten solder leaches away the solder pad (contact pad) destroying the thick/thin film circuit.
The problem with switches soldered to thick/thin film circuits is that they are too large and cumbersome in relationship to the size of the circuit in which they are used. This disadvantage is particularly significant in thick/thin film circuitry because in such circuits the switches may occupy more space than the rest of the circuit thereby placing a limit on the physical size thereof.
Finally switches which are outboarded require specialized circuitry and thus make the circuit more complex.
It is therefore an object of the present invention to provide an electrical switch mountable on a thick/thin film circuit arranged to be manipulated to selectively switch between elements on a thick/thin film circuit.